Synchronous neural oscillations in Parkinson’s disease: Variability and its potential network mechanisms

poster abstractRecent studies indicate that patterns of oscillatory synchronous activity in Basal Ganglia (BG) may be relevant to BG physiology and disorders, including Parkinson’s disease (PD). Oscillations in BG, in particular, in relation to motor control, are observed in different species, different conditions and different dopaminergic states (e.g., PD vs. normal). The rich membrane properties of BG neurons easily support oscillatory behavior. Correlations of oscillatory activity between different BG locations depend on the brain state and are dynamically organized. A general feature of BG oscillations is strong power and correlations of the β-band activity when no movement is performed and replacement of β with γ-band activity during movement. Dopamine-depleted state, such as PD, is marked by increase of oscillatory and synchronous activity, in particular in the β-band. This study explores the dynamical nature of these oscillations on short time-scales

Synchronous neural oscillations in Parkinson’s disease: Variability and its potential network mechanisms

poster abstractRecent studies indicate that patterns of oscillatory synchronous activity in Basal Ganglia (BG) may be relevant to BG physiology and disorders, including Parkinson’s disease (PD). Oscillations in BG, in particular, in relation to motor control, are observed in different species, different conditions and different dopaminergic states (e.g., PD vs. normal). The rich membrane properties of BG neurons easily support oscillatory behavior. Correlations of oscillatory activity between different BG locations depend on the brain state and are dynamically organized. A general feature of BG oscillations is strong power and correlations of the β-band activity when no movement is performed and replacement of β with γ-band activity during movement. Dopamine-depleted state, such as PD, is marked by increase of oscillatory and synchronous activity, in particular in the β-band. This study explores the dynamical nature of these oscillations on short time-scales

Acute d-Amphetamine alters the temporal patterning of intermittent synchronized oscillations in hippocampal and prefrontal circuits of the rat

poster abstractD-Amphetamine (d-AMPH) increases the bioavailability of numerous catecholamines, including dopamine, throughout the brain and modulates neural firing in cortical and subcortical regions. While a complex array of d-AMPH-mediated effects on firing have been reported, less is known regarding how d-AMPH affects the oscillatory properties of cortical circuits. In the current study, we simultaneously recorded local field potentials from electrode arrays implanted in the medial prefrontal cortex (PFC) and hippocampus (HC) of awake freely moving rats treated with saline, 1.0 mg/kg, or 3.3 mg/kg d-AMPH. The fine temporal structure of synchrony in delta, theta, beta, and gamma bands between these brain regions was examined to characterize how phase synchronization was altered by each dose of d-AMPH relative to saline. Differences were observed in the average level of phase-locking and in the variation of temporal patterns of synchrony on short (sub-second) time scales (including the distribution of durations of desynchronization events. In general, treatment with d-AMPH evoked higher levels of phase-locking. While this imperfect phase-locking can be potentially attained with both large number of short desynchronization episodes and small number of long desynchronization episodes, the data are marked by the dominance of short desynchronization episodes. These results suggest that within the HC and PFC, d-AMPH acts to increase synchronized oscillatory activity. The dominance of short desynchronization episodes suggests that the synchrony can be easily destabilized, yet it can be quickly re-established. The ease with which neural circuits can transition between synchronized and desynchronized dynamics may reflect altered information transfer regimes in these circuits and contribute to the spectrum of effects on cognition frequently observed with d-AMPH